中文说明：主成分分析是把多个指标化为少数几个终合指标的一种统计分析方法。本源代码为matlab中源代码，并添加了相应的分析注解
English Description：
Principal component analysis (PCA) is a statistical analysis method which transforms multiple indicators into a few final indicators. The source code for matlab source code, and added the corresponding analysis notes